The present invention is directed to the manufacture of identification cards for individual persons, such as drivers' licenses, credit cards, and the like. In particular, the present invention is concerned with the need to make such cards tamper-resistant, to prevent unauthorized use of an identification card by a person other than the person to whom the card pertains.
A relatively simple type of identification card for an individual typically contains textual data pertaining to the individual, such as name, address and date of birth, along with some type of identification number such as a driver's license number. In addition, the card may contain information regarding the physical attributes of the person, such as hair color, eye color, height and weight. Often, the card will also carry the person's signature. Unfortunately, it is quite difficult to prevent unauthorized use of this type of identification card by anyone who matches the general physical characteristics of the person described on the card. One approach to prevent unauthorized use is to require the person presenting the card to sign a piece of paper, and determine whether the signature matches that appearing on the card. However, with a little bit of practice an unauthorized user can learn to reproduce the signature on the card to an acceptable level, and thereby defeat efforts to prevent improper use.
As a further means to deter unauthorized use, more sophisticated identification cards include a picture of the person to whom they pertain. For example, it is quite common for most drivers' licenses to include a picture of the licensed driver thereon. This additional information on the card makes it significantly more difficult for the card to be readily used by a person other than the one to whom it pertains.
While offering a greater degree of security, identification cards which contain photographs are not foolproof. More particularly, these types of cards have been modified by removing the original photograph of the person to whom the card pertains and substituting a photograph of the unauthorized user. Unless a person to whom the card is presented personally knows the original cardholder, he is not apprised of the fact that the textual data and signature on the card do not pertain to the person whose photograph appears on the card.
In areas where security is a significant concern, highly sophisticated methods are employed to produce identification cards that are substantially tamper proof. For example, the cards may contain elements which are difficult to replicate, such as holograms, and/or they may be constructed of materials which are destroyed upon any attempt to tamper with the structure of the card. While these approaches may be feasible where areas of security is a high priority, their associated costs render them unsuitable for use in identification cards which are carried by a large segment of the population, such as drivers' licenses and credit cards.
It is therefore desirable to provide an inexpensive yet reliable approach to the manufacture of identification cards which renders the cards substantially tamper-resistant.